P4 nose tilting up and down while flying.

[jakobe75]

When flying forward the P4 tilts forward about 5 degrees forward and then tilts back, up down, up down, like it's correcting or scanning for something.

No objects in it's path, occurs randomly on the same course from one day to the next.

I cant seem to figure out why, tried to replicate to narrow down the variable of what would cause it, and I dont think it's the flying environment. Object sensing disabled and it still does it.

Doesnt do it left, right or backwards, only forwards.

- Active track and follow are not being used.
- No auto/ modes are being used. (tap fly, rth, ect)
- No heavy magnetic or radio interference near here that I am aware of, we hardly even have power lines. (even my cheap Baofeng UV5 handheld radios can reach 5 miles at times without much interference.)
- recalibrated, but issue remains.

I can visusally see the bird doing it, but I havent looked at the FPV while it occurs to see if the camera is catching it or staying on it's mark...and I havent been taking video at the time either.

- P4
- Nvidia Shield (android 6+)
- Dji Go app
- no mods

 

[Kirby Johnson]

When flying forward the P4 tilts forward about 5 degrees forward and then tilts back, up down, up down, like it's correcting or scanning for something.

No objects in it's path, occurs randomly on the same course from one day to the next.

I cant seem to figure out why, tried to replicate to narrow down the variable of what would cause it, and I dont think it's the flying environment. Object sensing disabled and it still does it.

Doesnt do it left, right or backwards, only forwards.

- Active track and follow are not being used.
- No auto/ modes are being used. (tap fly, rth, ect)
- No heavy magnetic or radio interference near here that I am aware of, we hardly even have power lines. (even my cheap Baofeng UV5 handheld radios can reach 5 miles at times without much interference.)
- recalibrated, but issue remains.

I can visusally see the bird doing it, but I havent looked at the FPV while it occurs to see if the camera is catching it or staying on it's mark...and I havent been taking video at the time either.

- P4
- Nvidia Shield (android 6+)
- Dji Go app
- no mods

Breastrstroke....Final Answer

 

[jakobe75]

Breastrstroke....Final Answer

Thats what it looks like!
It maintains steady altitude but dips down and "comes up for air" over and over!

 

[Kirby Johnson]

Jakobe : All kidding aside, about how fast is it doing it, say one second per up down cycle or much longer.
And how pronounced is the up..down, just a little bobble or a pretty severe gyration?

Take a video and let the smart guys here look at it.

 

[Kirby Johnson]

OK you were typing while I was asking questions. Is it throttle dependent? Does it do it at full or pretty heavy throttle, or just when you are going real slow.
Also i noticed you joined right after Christmas, Is that about how long you have had it? And has it done this from the beginning?

 

[jakobe75]

OK you were typing while I was asking questions. Is it throttle dependent? Does it do it at full or pretty heavy throttle, or just when you are going real slow.

Also I noticed you joined right after Christmas, Is that about how long you have had it? And has it done this from the beginning?

Half to full throttle in P mode, when it happens I havent put it in sport mode for fear of it crashing. But when it has been in sport mode I havent noticed it.

It hasnt done this from the beginning. I took a trip to northern PA about 2 weeks after I got and it was fine at home here in Georgia and then fine in PA as well. It started to happen when I came back.
Which made me think the compass was an issue, but It has been reclaibrated a few times since then and even a new tablet device being used.

 

[jakobe75]

Jakobe : All kidding aside, about how fast is it doing it, say one second per up down cycle or much longer.
And how pronounced is the up..down, just a little bobble or a pretty severe gyration?

Take a video and let the smart guys here look at it.

up down up down, about 5 degrees or so. In 1-2 second increments. Up for 1-2 seconds, then down for 1-2 seconds...rinse/repeat.

 

[Kirby Johnson]

OK Thanks J. I know enough to ask questions, but not enough to answer your question, I guess. I have the 3A and have not seen anything like this on mine, and I have the screw on prop gards too, which are known to possibly make it a little less stable. There are a handfull of guys on here who really know their stuff. Hopefully now you have enough information in this thread for one of them to see something of note.

 

[N017RW]

How about a vid of it in flight?

 

[jakobe75]

How about a vid of it in flight?

Hasnt happened while filming yet.

 

[jakobe75]

How about a vid of it in flight?

i might be able to catch on my cell on the next flight.

 

[jakobe75]

OK Thanks J. I know enough to ask questions, but not enough to answer your question, I guess. I have the 3A and have not seen anything like this on mine, and I have the screw on prop gards too, which are known to possibly make it a little less stable. There are a handfull of guys on here who really know their stuff. Hopefully now you have enough information in this thread for one of them to see something of note.

No prop guards here. Nothing appears to be obstructing the forward sensors either.

 

[Kirby Johnson]

How about a vid of it in flight?

Novemberzero-one-seven I will believe anything after that guy Jimmers whose bird ran away from home and landed on the Post Office front lawn the other day.

 

[N017RW]

i might be able to catch on my cell on the next flight.

That's what I meant. Not from on-board camera.

It's stabilized!!

 

[jwt873]

The sun can interfere with the P4's object avoidance sensors. If you're flying into a low sun at the right angle, the craft will bob around trying to 'avoid' the sun. You should see the distance warning arcs appearing on your device screen when this happens. It's fairly common.

Watch the front arms of my P4 bob up and down in the video below as it gets confused by the sun. This was on a Litchi mission and the throttle was held steady as it happened. If this is what you're seeing, then turning obstacle avoidance off, will prevent it.

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[jakobe75]

The sun can interfere with the P4's object avoidance sensors. If you're flying into a low sun at the right angle, the craft will bob around trying to 'avoid' the sun. You should see the distance warning arcs appearing on your device screen when this happens. It's fairly common.

Watch the front arms of my P4 bob up and down in the video below as it gets confused by the sun. This was on a Litchi mission and the throttle was held steady as it happened. If this is what you're seeing, then turning obstacle avoidance off, will prevent it.

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Maybe my issue too! thanks!

 

[jwt873]

And if it isn't the sun, it can't hurt to re calibrate the IMU.

 

[jakobe75]

And if it isn't the sun, it can't hurt to re calibrate the IMU.

I have recalibrated a few times. It still persists.

 

[dwallersv]

I had a similar problem while flying at a local softball field where it would seem to sort of "hitch" like some solid wall was suddenly popping into existence right in front of it and it was slamming on the brakes, then the wall disappeared a millisecond later. It sure seemed like the Obstacle Avoidance System was seeing phantom, spurious obstacles. The problem was worst during Active Track.

I calibrated the OAS this morning with DJI Assistant 2, and the problem's gone. It flies, avoids obstacles, and tracks perfectly now.

Try calibrating the OAS and Visual Positioning System and see if that fixes it. It's a bit more complicated than calibrating the compass or IMU, but isn't hard, follow the instructions and you can do it pretty easily. Your problem very well may be with the VP cameras being out of whack, given the elevation bobbing around. The VP calibration is exactly the same as the OAS calibration, and follows after OAS.

A tip: Note the location of the cameras for each calibration procedure, and center them on the computer screen when you hold the AC. This means the AC will not be centered -- the cameras, especially VP -- are off-center, but it is the cameras that need to be pointing at the center of the screen, not the geometry of the AC.

 

[jakobe75]

All calibrations had been done several times but I can do them again.

The elevation is not affected, the p4 stays perfectly level just tilts forward about 5 degrees and then back. Forward, back, forward, back. Or "nose up, nose down" But it stays on course.

I did not fly the P4 today even though the weather was great, I had retrieve a neighbor kids stuck walmart drone from my trees then install long range antennas on the wife's Hubsan X4 501s, then calibrate.